Process of producing metallic antimony and alloys of antimony and alkali metal arsenates



Patented .Fan. 3, 1928.

more STATES PATENT HARVEY M. BURKEY. OF PLAINFIELD, NEW JERSEY; ASSIGNOR TO AMERICAN METAL COMPANY, Llll, OF NEW YORK, N.

St, A CORPORATION on NEW YORK.

rnocnss OF PRODUCING METALLIC JANT IMON'Y niu-n ntnoys on ANTIMONY ANDALKALI META-L nnsn lflmrns.

No Drawing. Original application filed January 11,

1926, Serial No. 80,634. Divided and this application I filed October27, 1926. Serial No. 144,649.

This case is a division of my application Ser. No. 80,634, filed Jan.11, 1926.

This invention relates to the production of metallic antimony 'andalloys containing antimony and alkali metal arson-ates from crudematerials containing antimony and arsenic. It is applicable particularlyto the treatment of crude fumes derived from the treatment of orescontaining antimony and 1 arsenic. These fumes may be obtained from oresin which antimony or arsenic orbotll are the principal constituents orby roasting ores containing other constituents with small amounts ofantimony, arsenic or both of these metals.

Fumes containing antimony and arsenic are produced in a. number ofmetallurgical operations and have been treated heretofore in variousways to recover the valuable con- 2 stituents. The methods used arerelatively complicated and expensive. They do not permit, therefore, themost economical recovery of commercial products from the raw materials.

It is the object of the present invention to provide a. simple andetlectiveprocess of reducing antimony to a metallic form and ofcombining it if desired with other metals such as lead. The arsenic islikewise re covered in the form of an alkali metal orsenate which isevaluable commercial-compound.

I have discovered that the reduction of antimony from antimony trioxidecan be accomplished readily in a simple operation by mixing it with asuitable amount of arsenic trioxide and heating it in the presence ofalkali metal compound. lVhen such a. mixture is fused reactions occurwhich may be illustrated as follows:

lSb tiNzuAsO QH O.

These reactions are examples merely and other alkali compounds includingpotassium compounds can be utilized therein. The necessary proportionsof the reacting materials are determined by the molecular pro- Flyingmaterial containing crs' portions in the reactions and consequently theamounts of the material to be introduced can be readily calculated.

1n carrying out the invention the fume containing antimony and arsenic'trioxides can be derived from any source. 1h some cases both antimonyand arsenic are present in the fume but they are not likely to occur inthe required proportions. the mixture should be prepared to containarsenic and antimony in the molecular proportionsindicuted by thereactions, and to this mixture the required amount'of the alkali metalcompound should be added. The mixture is then fused in a suitablecrucible and upon the completion of the reaction the fusion willseparate into two layers, one of which is molten metallic antimony atthe bottom of the crucible. The alkali metal on senate is'in the upperlayer together with any excess of the alkali metal compound and the twolayers can be separately tapped from the crucible. The metallic antimonycan be utilized for any desired purpose. The alkali metal arscnate isrecovered by leaching and crystallization to separate the alkali metalarsenate from. the excess of other alkali metal compounds.

In many commercial operations the amount ofantimony trioxide availablefrom natural sources may not be suflicient to con- In any event vcrt allof the available arsenic trioxide in then fused and the reactionproceeds as above indicated if some antimony trioxide is included in themixture. When all of the antimony has separated air is blown into thecrucible beneath the molten antimony to corn gvcrt a portion thereofinto antimony triifibxide which. rises and mines v2-11 the oven .llCtrioxide and the alkali metal compourui. The antimony is again reducedend an additional quantity of the arsenic trioxide is converted into the:illcili metal arscnatc. The blowing of Hi1 continued until all of thearsenic lrioxiile has been converted. The layers are then pllllllllml toseparate so that the anti lI!( ll mm he withdrawn and the remainingmixture of alkali melul :irsenate will; the excess of othe alkali meialcompounds is l'lilli'llUll unil Cl" \5iillllZl"ll to recover theulliiuli uieliil ursenulc and the other alkali metal compounds can heturned to the process.

In another embodiment of the lIRVGIliZlQEi the fusion is carried on inthe presence of molten lczul in the bottom of the crucible. A layer ofthe alkali metal compound, for example. caustic soda, is melted 0:11 thesur face of the molten lead and the mixture of antimony and arsenictll0Xl(l8 is iiecl gradu ally while the bath is stirred. The reactionproceeds with the separation of metallic antimony which set-lies andalloys Willi the lead forming hard lead which is suitable-i r manycommercial uses. Alkali metal 531- senate is dissolved in the overlyinglayer of alkali metal compound and the latter is withdrawn and leachedto recover the alkali metal arsenate and the other alkali motelcompounds.

In the practice of tho iovenlion prefer so em loy sodium compounds suchas sodium cur onote or sodium hydroii'icle since these are most readilyavailable and are comparalively inexpensive. It is not necessary to use:1 single compound and the process can he conducted, for example, with amixture of sodium carbonate and sodium hydroxide or, for example, with2. mixture of sodium 113; diOXlClfi and sodium chloride. Any other saltcan he used as a carrier so long as it will fOlm a fusible sla with thealkali metal 11* senate at the Worliing temperature and will notinterfere with the recovery of the alkali metal arsenace by leaching andcrystallizelion.

Any suitable apparatus can be employecl in conducting the process, forexample, a reverberotory "furnace or suitable crucible for theproduction of metallic antimony or on iron crucible or pot for theproductio i of hard lemlwhen using a bat-h of lead and fusezl caustic.The reverberaiory furnace or crucible can be heated as usual ii the artto file temperature required which is above the, melting point of lead.

m Elle SIIIlPlBSi) up licalion oi the mveiilion s mixture of antimonylrioxicle anol arsonic triozide will; the required oropoitioii of sodiumcarbonate and preferzilily an excess of the lower is fused in thecrucible and healing is continued until the reaction is com le'te. Ifthe materials are introduced in tie proper proportions as indicated byihe reaction practically all of the antimony will separate as metallic:itimoiiy and all i, iii

rapidly when ilio oxidation of the flu is active, and if she amount 0":an: is neat sulliczen s the operation i ii longecl but the separationwill be cc ultimately if the air is blown into the Q). isle for asuficieiu'; period of time.

In preparing alloys of oulimony 13TGCS clescrihe, I prefer to usesocliur 5, dioxide, A considerable excess of this serial shoulclloemelted on halls of inc/liter lead, "for example, in the crucible themixture of antimony and arsenic should he iniirollucel then gradually omolten layer sodium liyclroziiie Willi cos tinned slirziug to eusui'edistribution consequent activity the o amount-oi antimony which is5565911; i i alloyed with the leacl will depend amount originallypresent in lilie introduced and upon the time during v the lead ispermitted to reuzain in He or ble.

The lead cam loo Witoclrawu when it contoins the clesireel amount oiantimony cuicl more laid can be added. to permit the com" plecion of thereaction and iuciclculzlly produce fHZlll-QX quantities of the lee Whilethe process as desci'ihei'l is particularly for the treatment of fumerived from ores containing antimony on sonic, it may he utilized inconverting a roomy and arsenic compounds resoecti inio metallic antimony01' alloys of mony and alkali metal orsenaies. Thu timony and arseniccompounds can ed and oxidized to produce the tri which are available foruse in the PlOcCo. described. 7

Various changes can be macle in i the operation without departinginveniion'oir sucriiiciug any of logos theroofi l chime- 1. The rocesswhich comprises iog the irloxicles oi finililllfialy sncl m the presenceof a fused mlzsli in pouno and s ineml adapted to alloy antimony. v

2. The process which com gtcises c the trioxicles of? antimony siiiclarse i presence of o fused alkali iucl=l col and mclien loco recesses Ie 3. The process which comprises combining mixture'of antimonyandsi'senic trioxides to the trioxides of antimony and arsenic'in the afused alkali metal compound in the prespresence of a fused alkali metalcompound once of a metal which is adapted to alloy 15 and a metaladaptedto alloy with the antiwith the antimony.

5 mony and separating the metal containing 6. '1 1e process whichcomprises reducingthe antimony from the fusion. I antimony trioxide bythe action of arsenic 4. The process which comprises combining trioxidein the presence of an alkali metal the tIiOXltlQS of antimony andarsenic in the compound 'and permitting the antimony to 20 presence of afused alkali metal compound alloy directly with a molten metal;

10 and molten lead and separating the lead com in testimony whereof Iaffix my signature. tainin the-antimony from'the fusion. 1 1 5. '1 1eprocess which comprises adding a. V HARVEY M. BURKEY.-

